Preparation of High-quality Oil from Vegetable Oil with High-free Fatty Acid (FFA) Content Using an Ammonia/Methanol Solution.

There are significant concerns regarding the quality of vegetable oils in the food and biofuel industries. In this study, we explored the preparation of high- quality oil from high-free fatty acid (FFA) vegetable oil using an ammonia/MeOH solvent as an alkali base. Among the six tested solvents, MeOH was the most suitable for the separation of the oil and FFAs. Among the three alkali bases, ammonia enhanced the miscibility of FFAs in MeOH by forming ammonium salts. The amounts of FFAs in the upper layer and oil in the lower layer were positively correlated (r = 0.9348 and 0.9617, respectively) with MeOH. With increasing MeOH concentration, the amount of oil in the lower layer increased along with the FFAs in the upper layer. Using the molar ratio of ammonia to FFA 1:1 and the ratio (v/w) of MeOH to oil 4:3, 91.6% FFAs and 97.8% oil in the upper and lower layers, respectively, were produced from 50% FFA oil. Using a relational expression of FFAs and oil in the upper layer, 97.1% FFAs and 99.6% oil in each layer was obtained from 10% FFA oil. The oil in the lower layer was further purified by extraction with MeOH. This method is easy and efficient for the separation and purification of oil, accompanied by the reuse of reagents with almost no loss of raw materials.

Screening of fatty acids, saccharides, and phytochemicals in Jatropha curcas seed kernel as their trimethylsilyl derivatives using gas chromatography/mass spectrometry.

Jatropha curcas is a multipurpose plant, of which the seed kernel oil (up to 60% content) has been exploited for BDF production. In this report, we explored the various kinds of minor compounds of saccharides, phytochemicals, fatty acids (FAs), and amino acids in the seed kernel using gas chromatography/mass spectrometry (GC/MS) as their trimethylsilyl (TMS) derivatives. The homogenized seed kernels were extracted with methanol, and the extract was distributed into ethyl acetate/water phase. The components of each layer were derivatized with N, O-bis (trimethylsilyl) trifluoroacetamide (BSTFA) and their TMS derivatives were screened by GC/MS analysis. In ethyl acetate layer, the four FAs of palmitic acid, oleic acid, linoleic acid, and stearic acid were identified with total content of 12 wt% in kernel. In addition, the two tocochromanols of γ-tocopherol and γ-tocotrienol, and three phytosterols of campesterol, stigmasterol, and ß-sitosterol were also identified. Meanwhile, as the main saccharide components, di-saccharide of sucrose with content of 3 wt% in kernel, tri-saccharide of raffinose, and sugar alcohol of sorbitol and myo-inositol, were identified in aqueous layer. Furthermore, metabolites of amino acid, and a series of metabolite were also identified. These results suggested that the Jatropha curcas seed kernel can be applied to cascade use for metallic soap, liquid fuel, food and medical supplement, and cosmetics in addition to biodiesel production.

Production of Biodiesel from Candlenut Oil Using a Two-step Co-solvent Method and Evaluation of Its Gaseous Emissions.

Candlenut oil (CNO) is a potentially new feedstock for biodiesel (BDF) production. In this paper, a two-step co-solvent method for BDF production from CNO was examined. Firstly, esterification of free fatty acids (FFAs) (7 wt%) present in CNO was carried out using a co-solvent of acetonitrile (30 wt%) and H2SO4 as a catalyst. The content of FFAs was reduced to 0.8 wt% in 1 h at 65°C. Subsequent transesterification of the crude oil produced was carried out using a co-solvent of acetone (20 wt%) and 1 wt% potassium hydroxide (KOH). Ester content of 99.3% was obtained at 40°C in 45 min. The water content in BDF was 0.023% upon purification using vacuum distillation at 5 kPa. The components of CNO BDF were characterized using a Fourier-transform infrared spectrometry and gas chromatography-flame ionization detector. The physicochemical properties of BDF satisfied the ASTM D6751-02 standard. The gaseous exhaust emissions from the diesel engine upon combustion of the BDF blends (B0-B100) with petrodiesel were examined. The emissions of carbon monoxide and hydrocarbons were clearly lower, but that of nitrogen oxides was higher in comparison to those from petro-diesel.

α-Glucosidase inhibitors from the stems of Embelia ribes.

From the ethyl acetate extract of the stems of Embelia ribes (Myrsinaceae), a new alkenylresorcinol, embeliphenol A (1), together with 11 known compounds have been isolated. Their structures were elucidated on the basis of spectroscopic data. All compounds possessed significant α-glucosidase inhibitory activity in a concentration-dependent manner, except for 2 and 9. Compounds 1, 3-6, 8, and 12 showed more potent inhibitory activity, with IC50 values ranging from 10.4 to 116.7 µM, than that of a positive control acarbose (IC50 , 214.5 µM).